Cognitive control of orofacial motor and vocal responses in the ventrolateral and dorsomedial human frontal cortex.

In the primate brain, a set of areas in the ventrolateral frontal (VLF) cortex and the dorsomedial frontal (DMF) cortex appear to control vocalizations. The basic role of this network in the human brain and how it may have evolved to enable complex speech remain unknown. In the present functional neuroimaging study of the human brain, a multidomain protocol was utilized to investigate the roles of the various areas that comprise the VLF-DMF network in learning rule-based cognitive selections between different types of motor actions: manual, orofacial, nonspeech vocal, and speech vocal actions. Ventrolateral area 44 (a key component of the Broca's language production region in the human brain) is involved in the cognitive selection of orofacial, as well as, speech and nonspeech vocal responses; and the midcingulate cortex is involved in the analysis of speech and nonspeech vocal feedback driving adaptation of these responses. By contrast, the cognitive selection of speech vocal information requires this former network and the additional recruitment of area 45 and the presupplementary motor area. We propose that the basic function expressed by the VLF-DMF network is to exert cognitive control of orofacial and vocal acts and, in the language dominant hemisphere of the human brain, has been adapted to serve higher speech function. These results pave the way to understand the potential changes that could have occurred in this network across primate evolution to enable speech production.

Acquisition and consolidation of implicit motor learning with physical and mental practice across multiple days of anodal tDCS.

BACKGROUND: Acquisition and consolidation of a new motor skill occurs gradually over long time span. Motor imagery (MI) and brain stimulation have been showed as beneficial approaches that boost motor learning, but little is known about the extent of their combined effects. OBJECTIVE: Here, we aimed to investigate, for the first time, whether delivering multiple sessions of transcranial direct current stimulation (tDCS) over primary motor cortex during physical and MI practice might improve implicit motor sequence learning in a young population. METHODS: Participants practiced a serial reaction time task (SRTT) either physically or through MI, and concomitantly received either an anodal (excitatory) or sham stimulation over the primary motor cortex during three successive days. The effect of anodal tDCS on the general motor skill and sequence specific learning were assessed on both acquisition (within-day) and consolidation (between-day) processes. We further compared the magnitude of motor learning reached after a single and three daily sessions of tDCS. RESULTS: The main finding showed that anodal tDCS boosted MI practice, but not physical practice, during the first acquisition session. A second major result showed that compared to sham stimulation, multiple daily session of anodal tDCS, for both types of practice, resulted in greater implicit motor sequence learning rather than a single session of stimulation. CONCLUSIONS: The present study is of particular importance in the context of rehabilitation, where we postulate that scheduling mental training when patients are not able to perform physical movement might beneficiate from concomitant and consecutive brain stimulation sessions over M1 to promote functional recovery.

Using real-time fMRI neurofeedback to restore right occipital cortex activity in patients with left visuo-spatial neglect: proof-of-principle and preliminary results.

Hemineglect is common after right parietal stroke, characterised by impaired awareness for stimuli in left visual space, with suppressed neural activity in the right visual cortex due to losses in top-down attention signals. Here we sought to assess whether hemineglect patients are able to up-regulate their right visual cortex activity using auditory real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback. We also examined any effect of this training procedure on neglect severity. Two different neurofeedback methods were used. A first group of six patients was trained to up-regulate their right visual cortex activity and a second group of three patients was trained to control interhemispheric balance between their right and left visual cortices. Over three sessions, we found that the first group successfully learned to control visual cortex activity and showed mild reduction in neglect severity, whereas the second group failed to control the feedback and showed no benefit. Whole brain analysis further indicated that successful up-regulation was associated with a recruitment of bilateral fronto-parietal areas. These findings provide a proof of concept that rt-fMRI neurofeedback may offer a new approach to the rehabilitation of hemineglect symptoms, but further studies are needed to identify effective regulation protocols and determine any reliable impact on clinical symptoms.

Goal Directed and Self-Control Systems in Bulimia Nervosa: An fMRI Study.

BACKGROUND: Binge eating is apparently the opposite of the strict control over food intake typically set by "maladaptive dieters". Using functional magnetic resonance imaging (fMRI), we investigated the role of goal-directed behaviors, and the related use of self-control, in binge-related food choices in patients with Bulimia Nervosa (BN). METHOD: While undergoing fMRI, women aged 18-35 with BN (N = 35) and healthy control women (N = 26) rated foods for healthiness and tastiness and then made food choices on a 5 points Likert scale between two conflicting options: one food with lower healthiness and higher tastiness (defined as uncontrolled choice) than the other food (defined as controlled choice). RESULTS: BN and healthy participants made more uncontrolled than controlled choices (63% vs 24% and 65% vs 18% respectively). While healthy participants used only food tastiness (chose tastier foods more often) to make food choices (p < .001), BN patients used both food healthiness (chose unhealthy food more often, p < .001) and food tastiness (p < .001) to make binge-related food choices. Activity in the ventromedial prefrontal cortex (vmPFC), which correlated with food choices (pFWE = 0.02), reflected this difference in the integration of food healthiness and food tastiness into a decision value. Functional connectivity analysis showed that the activity in the dorsolateral prefrontal cortex was coupled with vmPFC activity in uncontrolled food choices (pFWE = 0.03). INTERPRETATION: Contrary to what might be expected, not only food tastiness but also unhealthiness (a more abstract cognitive-based attribute than food tastiness) plays a role in uncontrolled choices in BN. These choices are likely goal-directed behaviors and recruit self-control.

Fear Spreading Across Senses: Visual Emotional Events Alter Cortical Responses to Touch, Audition, and Vision.

Attention and perception are potentiated for emotionally significant stimuli, promoting efficient reactivity and survival. But does such enhancement extend to stimuli simultaneously presented across different sensory modalities? We used functional magnetic resonance imaging in humans to examine the effects of visual emotional signals on concomitant sensory inputs in auditory, somatosensory, and visual modalities. First, we identified sensory areas responsive to task-irrelevant tones, touches, or flickers, presented bilaterally while participants attended to either a neutral or a fearful face. Then, we measured whether these responses were modulated by the emotional content of the face. Sensory responses in primary cortices were enhanced for auditory and tactile stimuli when these appeared with fearful faces, compared with neutral, but striate cortex responses to the visual stimuli were reduced in the left hemisphere, plausibly as a consequence of sensory competition. Finally, conjunction and functional connectivity analyses identified 2 distinct networks presumably responsible for these emotional modulatory processes, involving cingulate, insular, and orbitofrontal cortices for the increased sensory responses, and ventrolateral prefrontal cortex for the decreased sensory responses. These results suggest that emotion tunes the excitability of sensory systems across multiple modalities simultaneously, allowing the individual to adaptively process incoming inputs in a potentially threatening environment.

How does reward compete with goal-directed and stimulus-driven shifts of attention?

In order to behave adaptively, attention can be directed in space either voluntarily (i.e. endogenously) according to strategic goals, or involuntarily (i.e. exogenously) through reflexive capture by salient or novel events. The emotional or motivational values of stimuli can also influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms. Here we designed a visual search paradigm in which goal-driven and stimulus-driven shifts of attention were manipulated by classic spatial cueing procedures, while an irrelevant, but previously rewarded stimulus also appeared as a distractor and hence competed with both types of spatial attention during search. Our results demonstrated that stimuli previously associated with a high monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, mitigating the attentional orienting induced by both endogenous and exogenous cues.

How emotion context modulates unconscious goal activation during motor force exertion.

Priming participants with emotional or action-related concepts influences goal formation and motor force output during effort exertion tasks, even without awareness of priming information. However, little is known about neural processes underpinning how emotional cues interact with action (or inaction) goals to motivate (or demotivate) motor behaviour. In a novel functional neuroimaging paradigm, visible emotional images followed by subliminal action or inaction word primes were presented before participants performed a maximal force exertion. In neutral emotional contexts, maximum force was lower following inaction than action primes. However, arousing emotional images had interactive motivational effects on the motor system: Unpleasant images prior to inaction primes increased force output (enhanced effort exertion) relative to control primes, and engaged a motivation-related network involving ventral striatum, extended amygdala, as well as right inferior frontal cortex. Conversely, pleasant images presented before action (versus control) primes decreased force and activated regions of the default-mode network, including inferior parietal lobule and medial prefrontal cortex. These findings show that emotional context can determine how unconscious goal representations influence motivational processes and are transformed into actual motor output, without direct rewarding contingencies. Furthermore, they provide insight into altered motor behaviour in psychopathological disorders with dysfunctional motivational processes.

The Sequential Binge, a New Therapeutic Approach for Binge Eating: A Pilot Study.

BACKGROUND AND OBJECTIVES: A sizeable proportion of patients experiencing binge eating do not respond to cognitive behavioral therapy (CBT). We present the sequential binge (SB), a new behavioral intervention that complements CBT, and preliminary results of its effects. SB breaks up the binge into repeated identical sequences of eating separated by incremental pauses. This pattern of ingestion aims at facilitating boredom toward the ingested foods and at turning cognitive control away from binge food restriction. SB is hypothesized to reduce food intake during the binge and the number of daily binges. METHODS: Prospective pilot study. Fifteen binging patients with previous unsuccessful intensive CBT were given SB as an adjunct to their treatment and were followed up for 16 weeks from admission. All patients were reassessed 47 weeks on average after discharge. RESULTS: SB was associated with a 44% relative reduction in the planned food intake (p<0.001), a longer consecutive binge refractory period compared to regular binges (median: 48 hours versus 4 hours, p = 0.002) and an average relative reduction by 26% of binge number the day after each SB (p = 0.004). 47% of patients reached binge abstinence for four consecutive weeks 16 weeks after the first SB. CONCLUSION: This case series shows promising evidence for the use of SB in patients with refractory binge eating. Further evaluation in a prospective randomized controlled trial would be justified.

How Does Awareness Modulate Goal-Directed and Stimulus-Driven Shifts of Attention Triggered by Value Learning?

In order to behave adaptively, attention can be directed in space either voluntarily (i.e., endogenously) according to strategic goals, or involuntarily (i.e., exogenously) through reflexive capture by salient or novel events. The emotional or motivational value of stimuli can also strongly influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms, particularly outside of awareness. Here we developed a visual search paradigm to study subliminal value-based attentional orienting. We systematically manipulated goal-directed or stimulus-driven attentional orienting and examined whether an irrelevant, but previously rewarded stimulus could compete with both types of spatial attention during search. Critically, reward was learned without conscious awareness in a preceding phase where one among several visual symbols was consistently paired with a subliminal monetary reinforcement cue. Our results demonstrated that symbols previously associated with a monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, and despite reward being unconsciously acquired. Thus, motivational processes operating independent of conscious awareness may provide powerful influences on mechanisms of attentional selection, which could mitigate both stimulus-driven and goal-directed shifts of attention.

Preference for Safe Over Risky Options in Binge Eating.

Binge eating has been usually viewed as a loss of control and an impulsive behavior. But, little is known about the actual behavior of binging patients (prevalently women) in terms of basic decision-making under risk or under uncertainty. In healthy women, stressful cues bias behavior for safer options, raising the question of whether food cues that are perceived as threatening by binging patients may modulate patients' behaviors towards safer options. A cross-sectional study was conducted with binging patients (20 bulimia nervosa (BN) and 23 anorexia nervosa binging (ANB) patients) and two control groups (22 non-binging restrictive (ANR) anorexia nervosa patients and 20 healthy participants), without any concomitant impulsive disorder. We assessed decisions under risk with a gambling task with known probabilities and decisions under uncertainty with the balloon analog risk taking task (BART) with unknown probabilities of winning, in three cued-conditions including neutral, binge food and stressful cues. In the gambling task, binging and ANR patients adopted similar safer attitudes and coherently elicited a higher aversion to losses when primed by food as compared to neutral cues. This held true for BN and ANR patients in the BART. After controlling for anxiety level, these safer attitudes in the food condition were similar to the ones under stress. In the BART, ANB patients exhibited a higher variability in their choices in the food compared to neutral condition. This higher variability was associated with higher difficulties to discard irrelevant information. All these results suggest that decision-making under risk and under uncertainty is not fundamentally altered in all these patients.

Body mass index kinetics around adiposity rebound in Anorexia nervosa: A case-control study.

BACKGROUND AND OBJECTIVE: Anorexia nervosa (AN) is associated with parameters involved in body mass index (BMI) regulation. Contrary to obesity, BMI kinetics around the adiposity rebound is not documented in AN. This study aimed at investigating which characteristics of BMI kinetics around the adiposity rebound are associated with AN. METHODS: Multicentre case-control study with 101 inpatient women with AN onset after 10 years of age, and 101 healthy women, all free of overweight history and matched for age, level of education and fathers' socio-professional status. Age at adiposity rebound, pre- and post-adiposity rebound BMI velocities and accelerations (change in velocity over time) were estimated with linear mixed models using data recorded between 2 and 10 years of age. RESULTS: Patients had an earlier adiposity rebound (mean (standard deviation (SD)): 5.3 (1.3) vs 5.7 (1.1) years), a larger BMI at adiposity rebound (mean (SD): 15.3 [1] vs 14.9 (0.9) kg/m2) and 29% lower BMI acceleration after adiposity rebound than controls. After adjustment, only BMI at adiposity rebound and BMI acceleration after adiposity rebound were associated with a higher risk of AN (Odds ratio [95% confidence interval]: 2.15 [1.41-3.46] for an increase of 1 kg/m2 and 2.44 [1.56-4.02] for an increase of 0.1 kg/(m2*years2) respectively). These two factors were not correlated in patients (r = 0.007, p = 0.96). CONCLUSIONS: A flattened evolution of BMI after adiposity rebound and higher BMI at adiposity rebound were associated with AN. Further prospective study is needed to confirm these findings.

Improved planning abilities in binge eating.

OBJECTIVE: The role of planning in binge eating episodes is unknown. We investigated the characteristics of planning associated with food cues in binging patients. We studied planning based on backward reasoning, reasoning that determines a sequence of actions back to front from the final outcome. METHOD: A cross-sectional study was conducted with 20 healthy participants, 20 bulimia nervosa (BN), 22 restrictive (ANR) and 23 binging anorexia nervosa (ANB), without any concomitant impulsive disorder. In neutral/relaxing, binge food and stressful conditions, backward reasoning was assessed with the Race game, promotion of delayed large rewards with an intertemporal discounting task, attention with the Simon task, and repeating a dominant behavior with the Go/No-go task. RESULTS: BN and to a lower extent ANB patients succeeded more at the Race game in food than in neutral condition. This difference discriminated binging from non-binging participants. Backward reasoning in the food condition was associated with lower approach behavior toward food in BN patients, and higher food avoidance in ANB patients. Enhanced backward reasoning in the food condition related to preferences for delayed large rewards in BN patients. In BN and ANB patients the enhanced success rate at the Race game in the food condition was associated with higher attention paid to binge food. CONCLUSION: These findings introduce a novel process underlying binges: planning based on backward reasoning is associated with binges. It likely aims to reduce craving for binge foods and extend binge refractory period in BN patients, and avoid binging in ANB patients. Shifts between these goals might explain shifts between eating disorder subtypes.

Discrete sequence production with and without a pause: the role of cortex, basal ganglia, and cerebellum.

Our sensorimotor experience unfolds in sequences over time. We hypothesize that the processing of movement sequences with and without a temporal pause will recruit distinct but cooperating neural processes, including cortico-striatal and cortico-cerebellar networks. We thus, compare neural activity during sequence learning in the presence and absence of this pause. Young volunteer participants learned sensorimotor sequences using the discrete sequence production (DSP) task, with Pause, No-Pause, and Control sequences of four elements in an event related fMRI protocol. The No-Pause and Pause sequences involved a more complex sequential structure than the Control sequence, while the Pause sequences involved insertion of a temporal pause, relative to the No-Pause sequence. The Pause vs. No-Pause contrast revealed extensive fronto-parietal, striatal, thalamic and cerebellar activations, preferentially for the Pause sequences. ROI analysis indicated that the cerebellum displays an early activation that was attenuated over successive runs, and a significant preference for Pause sequences when compared with caudate. These data support the hypothesis that a cortico-cerebellar circuit plays a specific role in the initial processing of temporal structure, while the basal ganglia play a more general role in acquiring the serial response order of the sequence.

The location of feedback-related activity in the midcingulate cortex is predicted by local morphology.

Information processing in the medial frontal cortex is often said to be modulated in pathological conditions or by individual traits. This has been observed in neuroimaging and event-related potential studies centered in particular on midcingulate cortex (MCC) functions. This region of the brain is characterized by considerable intersubject morphological variability. Whereas in a subset of hemispheres only a single cingulate sulcus (cgs) is present, a majority of hemispheres exhibit an additional sulcus referred to as the paracingulate sulcus (pcgs). The present functional magnetic resonance imaging study defined the relationship between the local morphology of the cingulate/paracingulate sulcal complex and feedback-related activity. Human subjects performed a trial-and-error learning task in which they had to discover which one of a set of abstract stimuli was the best option. Feedback was provided by means of fruit juice, as in studies with monkeys. A subject-by-subject analysis revealed that the feedback-related activity during exploration was systematically located in the cgs when no pcgs was observed, but in the pcgs when the latter sulcus was present. The activations had the same functional signature when located in either the cgs or in the pcgs, confirming that both regions were homologues. Together, the results show that the location of feedback-related MCC activity can be predicted from morphological features of the cingulate/paracingulate complex.

Reputational priors magnify striatal responses to violations of trust.

Humans learn to trust each other by evaluating the outcomes of repeated interpersonal interactions. However, available prior information on the reputation of traders may alter the way outcomes affect learning. Our functional magnetic resonance imaging study is the first to allow the direct comparison of interaction-based and prior-based learning. Twenty participants played repeated trust games with anonymous counterparts. We manipulated two experimental conditions: whether or not reputational priors were provided, and whether counterparts were generally trustworthy or untrustworthy. When no prior information is available our results are consistent with previous studies in showing that striatal activation patterns correlate with behaviorally estimated reinforcement learning measures. However, our study additionally shows that this correlation is disrupted when reputational priors on counterparts are provided. Indeed participants continue to rely on priors even when experience sheds doubt on their accuracy. Notably, violations of trust from a cooperative counterpart elicited stronger caudate deactivations when priors were available than when they were not. However, tolerance to such violations appeared to be mediated by prior-enhanced connectivity between the caudate nucleus and ventrolateral prefrontal cortex, which anticorrelated with retaliation rates. Moreover, on top of affecting learning mechanisms, priors also clearly oriented initial decisions to trust, reflected in medial prefrontal cortex activity.